Showing 4 results for Eccentricity
A. Damaki Aliabad, M. Mirsalim, M. Fazli Aghdaei,
Volume 6, Issue 1 (3-2010)
Abstract
The air-gap of electrical machines may become non-uniform due to low accuracy of the manufacturing machinery, in assembling processes, or by aging. Detection and monitoring of this phenomenon is very important and of interest. There are several methods to model non-uniform air-gaps and to detect them by monitoring systems. One of the most widely used methods is by the analysis of the line currents. In this paper a new, simple and comprehensive method is presented to model and detect non-uniform air-gaps in synchronous generators with skewed rotors. The influence of non-uniform air-gaps on the harmonics of the induced voltage of the stator is investigated by the proposed method. Simulations are performed for three cases: uniform air-gap, static rotor eccentricity, and stator ovality in a two phase generator. The experimental results are also presented. The good correspondence between the simulation and the experimental results clearly validates the theoretical findings put forward in this paper.
F. Tootoonchian, K. Abbaszadeh, M. Ardebili,
Volume 8, Issue 3 (9-2012)
Abstract
Resolvers are widely used in electric driven systems especially in high precision servomechanisms. Both encapsulated and pancake resolvers suffer from a major drawback: static eccentricity (SE). This drawback causes a significant increase in resolver output position error (RPE) which could not be corrected electronically. To reduce RPE, this paper proposes a novel structure with axial flux. Proposed topology, design guidelines, optimization procedure and several key features to improve the sensitivity of axial flux resolver (AFR) against SE are studied. Furthermore, to minimize RPE an optimized design is attained. The machines are investigated in detail by using d-q model and 3D time stepping finite-element analysis. The results of theses two methods are compared and both prototype machines (proposed and optimized) are built. In order to evaluate proposed topologies, an experimental test setup is devised. Finally, the experimental results of the prototype machines verified the analysis results.
F. Tootoonchian, F. Zare,
Volume 14, Issue 3 (9-2018)
Abstract
Disk Type Variable Reluctance (DTVR) resolvers have distinguished performance under run out fault comparing to conventional sinusoidal rotor resolvers. However, their accuracy under inclined rotor fault along with different types of eccentricities includes static and dynamic eccentricities are questioned. Furthermore, due to thin copper wires that are used for signal and excitation coils of resolver there is high risk of short circuit fault in the coils. So, in this study the performance of the sinusoidal rotor DTVR resolver under the mentioned faults are studied. The quality of output voltages along with position error of the sensor is discussed. 3-D time stepping finite element method is used to show the effect of different faults. Finally, the prototype of the studied resolver is constructed and tested. The employed test bed is built in such a way that is able to apply controllable level of different mechanical faults. Good agreement is obtained between the finite element and the experimental results, validating the success of the presented analysis.
V. Naeini, M. Moomeni,
Volume 19, Issue 1 (3-2023)
Abstract
This paper introduces the modeling and fault diagnosis of rotor eccentricities of permanent magnetic synchronous machine (PMSM). The modeling of machine in healthy and fault condition have been proposed based on magnetic equivalent circuit (MEC). Nevertheless, the research methods of diagnosis and modeling are common, this paper tends to provide a fast computation and more detailed model with reasonable degree of accuracy. Firstly, the MEC modeling of PMSM in the electric and magnetic fields are introduced and next, the different fault conditions are carried out. Also to consider the eccentricity fault of an interior mounted PMSM, a methodology based on MEC is proposed. The accuracy of this model will be verified by comparing with identical results obtained by finite element method (FEM).
